1. Field of the Invention
Single-dose active ingredient preparations mean preparations which contain a predetermined amount of active substance in separate reaction units which can be handled individually.
An active ingredient for the purpose of this invention may be understood to be, for example, a medicinal substance, an insecticide, a pesticide, a reagent, etc.
2. Description of the Related Art
If an active substance names, for example, a medical active ingredient, such single-dose pharmaceutical forms are, for example, tablets, capsules, suppositories or transdermal therapeutic systems (TTS).
Non-single-dose pharmaceutical forms would be, for example, sprays, syrups, ointments and drops, with which the actual dosage takes place only immediately before use.
In single-dose active ingredient preparations, the active ingredient is to be processed in an appropriate amount together with any excipients necessary to give the active ingredient preparations ready for use. This technology can be regarded as mature for the production of tablets and capsules. Modern tablet presses and capsule-filling machines guarantee a high production rate and very accurate metering in the range 95-105% of the specification.
Transdermal therapeutic systems are still a relatively recent pharmaceutical form which is used externally in the form of a plaster on the skin and delivers the active ingredient through the skin to the body. Special metering techniques are used to produce these TTS, and further innovations in terms of new metering techniques are possible.
In one embodiment of these TTS, the active ingredient is contained directly in the adhesive and, during production, is metered together with the adhesive two-dimensionally onto a sheet.
This means that TTS are the only pharmaceutical form for which it is important to meter a medicinal active ingredient onto a predetermined area in a predetermined amount. Considering non-medicinal active ingredients such as, for example, insecticides, pesticides or reagents, two-dimensional preparations in the form of impregnated papers, sheets or boards have been known for a long time. However, the demands on the accuracy of metering in the area for these applications are not great.
The present invention is based on the object of providing a method for metering active ingredients in powder form onto a redetermined area.
This object is achieved with the use of the techniques known from the dry copying process by a method in which the active ingredient is transferred as electrically charged powder to a roll with the opposite charge, then the active ingredient is transferred from the roll to a two-dimensional substrate with an electric charge opposite to the active ingredient, and the active ingredient transferred to the substrate is fixed by means of a heat treatment.
It has emerged that this technique is capable of metering active ingredients in powder form onto an area with an accuracy sufficient for medicinal products. This is directly discernible with color copying, in which each color is metered separately, and major inaccuracies would result in wrong colors.